U.S. patent application number 11/119284 was filed with the patent office on 2005-11-03 for suspension strut top mount.
This patent application is currently assigned to ZF Friedrichshafen AG. Invention is credited to Handke, Gunther, Schulz, Markus.
Application Number | 20050242542 11/119284 |
Document ID | / |
Family ID | 34935334 |
Filed Date | 2005-11-03 |
United States Patent
Application |
20050242542 |
Kind Code |
A1 |
Handke, Gunther ; et
al. |
November 3, 2005 |
Suspension strut top mount
Abstract
A suspension strut top mount having a bearing connection onto a
vehicle body and a spring retainer for a vehicle support. The
spring retainer is set obliquely relative to a central axis of a
suspension strut. The suspension strut top mount further has an
obliquely set bearing arranged between the bearing connection and
the spring retainer and has a bearing input part, which is
associated with the bearing connection, and a bearing output part,
which is associated with the spring retainer. A stop buffer, which
is arranged concentrically to the central axis of the suspension
strut, comes into contact on a cylinder-end surface of the
suspension strut in a defined spring compression position. The stop
buffer has an effective connection to the bearing output part of
the bearing.
Inventors: |
Handke, Gunther; (Euerbach,
DE) ; Schulz, Markus; (Remscheid, DE) |
Correspondence
Address: |
COHEN, PONTANI, LIEBERMAN & PAVANE
551 FIFTH AVENUE
SUITE 1210
NEW YORK
NY
10176
US
|
Assignee: |
ZF Friedrichshafen AG
|
Family ID: |
34935334 |
Appl. No.: |
11/119284 |
Filed: |
April 29, 2005 |
Current U.S.
Class: |
280/124.155 |
Current CPC
Class: |
B60G 2204/61 20130101;
B60G 15/068 20130101; F16F 9/38 20130101; B60G 2204/43 20130101;
B60G 2204/44 20130101; F16F 9/58 20130101; B60G 2204/124 20130101;
B60G 2204/1242 20130101; B60G 2204/128 20130101; B60G 2204/418
20130101; B60G 2200/46 20130101; B60G 15/063 20130101; B60G
2204/4502 20130101; F16F 9/54 20130101 |
Class at
Publication: |
280/124.155 |
International
Class: |
B60G 015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 30, 2004 |
DE |
10 2004 021 497.2 |
Claims
What is claimed is:
1. A suspension strut top mount for connection onto a vehicle body,
comprising: a bearing connection coupled to the vehicle body; a
strut assembly extending along an axis and comprising a cylinder,
wherein the cylinder and the bearing connection are operative to
axially displace relative to one another in response to applying an
external force, the cylinder having an end surface opposing to and
axially spaced from the bearing connection; a bearing mounted to
the strut assembly obliquely relative to the axis, the bearing
comprising an input part coupled to the bearing connection and an
output part; a spring retainer seated against the output part of
the bearing obliquely relative to the axis; a vehicle spring
supported by the spring retainer and spaced radially outwards from
the strut assembly, the vehicle spring being compressible to a
predetermined position in response to the external force; and a
stop buffer positioned between the vehicle spring and the strut
assembly, the stop buffer being operatively connected to the output
part of the bearing and displaceable therewith towards the cylinder
in response to the external force so that the stop buffer abuts the
cylinder end surface upon compressing the vehicle spring to the
predetermined position.
2. The suspension strut top mount of claim 1, wherein the strut
assembly has a steering axis extending transversely to the axis,
the bearing being centered about a bearing axis substantially
aligned with the steering axis.
3. The suspension strut top mount of claim 1, wherein the spring
retainer has an axially extending surface juxtaposed with and
radially supporting the stop buffer.
4. The suspension strut top mount of claim 3 further comprising an
axially extending tubular protective sleeve surrounding the stop
buffer, the spring retainer having a retention surface configured
to support one of opposite axial ends of the tubular protective
sleeve.
5. The suspension strut top mount of claim 1, wherein the bearing
output part has a radially extending support surface axially
supporting one of opposite axial ends of the stop buffer.
6. The suspension strut top mount of claim 5, wherein the support
surface extends perpendicular to the axis of the strut
assembly.
7. The suspension strut top mount of claim 1, wherein the spring
retainer and the bearing output part of the bearing have axially
juxtaposed surfaces pressing against one another so as to couple
the spring retainer and the bearing output part to one another.
8. The suspension strut top mount of claim 1 further comprising a
reinforcement sleeve extending axially between the spring retainer
and the stop buffer and configured to support the spring
retainer.
9. The suspension strut top mount of claim 8, wherein the
reinforcement sleeve has an annular end extending radially inwards
towards the strut assembly and supported on the bearing output
part.
10. The suspension strut top mount of claim 8 further comprising a
snap connection unit mounted between the reinforcement sleeve and
the stop buffer.
11. The suspension strut top mount of claim 8, wherein the
reinforcement sleeve has an angled edge section extending radially
outwards from the stop buffer and axially supported on the spring
retainer.
12. The suspension strut top mount of claim 11 further comprising a
tubular protective element extending axially from the angled edge
section and supported thereon.
13. The suspension strut top mount of claim 10, wherein the angled
edge section comprises a circumferentially continuous angled
section or a plurality of circumferentially spaced apart angled
subsections.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a suspension strut top mount for
use in a vehicle body.
[0003] 2. Description of the Related Art
[0004] U.S. 2003/0006574 A1 discloses a suspension strut top mount
for connection onto a vehicle body which has a bearing between a
spring retainer and a bearing connection to the vehicle body. A
second spring retainer is fastened at the cylinder end, the
cylinder synchronously executing a pivoting motion during a
steering motion of a vehicle wheel. The pivoting motion is
transferred to the bearing-end spring retainer by a vehicle support
spring, which is restrained between the two spring retainers. The
bearing prevents restraint from occurring within the bearing, which
reduces comfort, on the one hand, and has a negative effect on the
life of the suspension strut top mount on the other.
[0005] The central axes of the bearing-end spring retainer and the
bearing extend identically with the steering axis of the vehicle
wheel. This measure is intended to prevent disturbing steering
torques, which can cause an out-of-track motion of the vehicle.
[0006] The suspension strut top mount forming the generic type also
has a stop buffer which, relative to the force path within the
suspension strut top mount, is axially supported parallel to the
bearing. In the case of superimposed spring compression and
steering motions, a condition can occur where the stop buffer lands
on a cylinder-end surface of the suspension strut and blocks the
pivoting motion capability of the bearing on the spring
retainer.
[0007] So that this problem does not occur, DE 83 11 927 U1
discloses that the stop buffer can execute a twisting motion
relative to the cylinder by means of a second bearing. Such a
second bearing, however, represents substantial cost and
installation space expenditure.
SUMMARY OF THE INVENTION
[0008] The object of the present invention is to realize a
vibration damper which, in the case of an obliquely set bearing
within a suspension strut top mount, solves the blocking problem,
in association with a stop buffer, known from the prior art.
[0009] According to the invention, the object is achieved by the
stop buffer's having an effective connection to the bearing output
part of the bearing.
[0010] The major advantage of the invention consists in the fact
that the stop buffer can execute a relative motion in the
peripheral direction with respect to the suspension strut without a
blockage and restraint situation occurring within the suspension
strut top mount. The technical requirement is also very simple
because, with only one bearing, the complete suspension strut top
mount, including the spring retainer, is rotationally decoupled
from the cylinder of the suspension strut.
[0011] In a further advantageous embodiment, the central axis of
the obliquely set bearing and a steering axis of the suspension
strut are aligned so as to be at least approximately coincident.
Comprehensive tests have shown that, despite the angular setting
between the stop buffer and the steering axis, about which the
suspension strut pivots during a steering motion, no clamping
forces or friction forces occur between the stop buffer and a
piston rod of the suspension strut.
[0012] Provision is made for the spring retainer to have an outer
surface on which the stop buffer is radially supported. For this
purpose, the spring retainer has a sleeve section, which extends
concentrically with the central axis of the suspension strut.
[0013] In addition, the spring retainer has a retention surface for
a tubular protective element enveloping the stop buffer. As a
consequence, no torsional loads occur within the protective element
either so that the protective element can be connected at one end
to the cylinder of the suspension strut.
[0014] The bearing output part has a support surface for the axial
support of the stop buffer. To avoid transverse forces, the support
surface is aligned at right angles to a central axis of the
suspension strut.
[0015] With a view to a simple assembly procedure, the spring
retainer and the bearing output part form a press connection by
means of axially extending clamping surfaces. The spring retainer
and the bearing output part can form a structural unit which can be
pre-assembled. The structural unit can be produced independently of
a specified cycle time within an assembly procedure of the overall
suspension strut.
[0016] The spring retainer should preferably consist of a plastic.
So that, nevertheless, even very large forces can be transferred to
the bearing output part, a reinforcement sleeve for the spring
retainer is arranged between the stop buffer and the spring
retainer.
[0017] The reinforcement sleeve has an annular end, which is
supported on the bearing output part. This measure additionally
stiffens the reinforcement sleeve and offers the possibility of
employing a relatively thin-walled bearing output part.
[0018] To axially secure the stop buffer to the suspension strut
top mount, a snap connection is present between the reinforcement
sleeve and the stop buffer.
[0019] The reinforcement sleeve has at least angled edge sections,
possibly also a completely circumferential edge, which are axially
supported on the spring retainer.
[0020] The at least angled edge sections of the reinforcement
sleeve provide a further retention surface for the tubular
protective element. As a consequence, two alternately effective
retention surfaces are present for the tubular protective element,
so that a clearance-free fastening is possible between the
protective element and the suspension strut top mount.
[0021] Other objects and features of the present invention will
become apparent from the following detailed description considered
in conjunction with the accompanying drawings. It is to be
understood, however, that the drawings are designed solely for
purposes of illustration and not as a definition of the limits of
the invention, for which reference should be made to the appended
claims. It should be further understood that the drawings are not
necessarily drawn to scale and that, unless otherwise indicated,
they are merely intended to conceptually illustrate the structures
and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention is explained in more detail using the
following description of the figure, which illustrates an axial
sectional view of the invention suspension strut.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0023] The figure shows a suspension strut top mount 1 for a
suspension strut 3, of which only an upper partial region is shown.
The suspension strut top mount has a bearing connection 5 to a
vehicle body, which is not shown. By means of its cup-shaped
three-dimensional shape, the bearing connection 5 accommodates an
elastomer body 7, which at least partially encloses a connecting
ring 9 on the outside, the connecting ring having an axial and
torsion-proof connection to a piston rod 11 of the suspension
strut.
[0024] On the outside, the bearing connection has a further
elastomer body 13, on which a bearing 15 is supported axially and
radially. The bearing 15 is aligned obliquely with its central axis
at least approximately coincident with a steering axis 16.
Compensation for centrifugal forces has to be achieved by the
obliquely set bearing 15 without the bearing itself being
critically loaded. The steering axis 16 encloses an angle .alpha.
with a central axis 19 of the suspension strut 3. The bearing 15
comprises a bearing input part 15a and a bearing output part 15b,
which parts can execute a rotational motion relative to one
another. For the invention, it is unimportant whether a rolling
contact bearing or a sliding bearing is used. A spring retainer 17
for a vehicle support spring 21, which is in contact at its other
end with a cylinder-end spring retainer 23, is supported on the
bearing output part 15b. The central axis of the vehicle support
spring is also at least approximately aligned identically to the
steering axis 16. The spring retainer 17, which is preferably
manufactured from a plastic, has a sleeve section 25 so that,
between the spring retainer 17 and an offset region of the bearing
output part 15b clamping surfaces 27, 29, a press connection is
present between the bearing output part 15b and the spring retainer
17.
[0025] A stop buffer 31 is arranged concentrically with the central
axis 19 of the suspension strut 3, which stop buffer 31 comes into
contact, from a defined spring compression position of the piston
rod 11 in a cylinder 33, with a cylinder-end surface 35 of the
suspension strut which, in this case, is formed by an additional
cap 37. The stop buffer 31 has effective connection with the
bearing output part 15b of the bearing 15, so that these two parts
move synchronously, axially and in the peripheral direction.
[0026] The spring retainer 17, in particular the sleeve section 25,
has a surface 39 on which the stop buffer 31 is radially supported.
A support surface 41 of the bearing output part 15b, which support
surface 41 is aligned at right angles to the central axis 19 of the
suspension strut, provides axial support. The internal diameter of
the stop buffer 31 and the piston rod 11 form a free annular space
42 in order to avoid a rubbing contact between the piston rod 11
and the stop buffer 31.
[0027] A reinforcement sleeve 43 is arranged between the stop
buffer 31 and the spring retainer 17. This reinforcement sleeve has
an annular end, 45, which is axially supported on the bearing
output part 15b. The reinforcement sleeve 43 and the stop buffer 31
form a snap connection 47 which, for example, contains radially
inwardly directed beads of the reinforcement sleeve 43, which beads
engage in a groove of the stop buffer.
[0028] The piston rod 11 and the stop buffer 31 are enveloped by a
tubular protective element 49, in this exemplary embodiment an
axially elastic bellows, the protective element 49 being axially
supported at one end on a retention surface 51 of the spring
retainer 17. The reinforcement sleeve 43 has at least angled edge
sections 53, possibly a completely circumferential edge, which edge
is supported at the end on the spring retainer 17, this edge
providing a further retention surface 55 for the tubular protective
element 49.
[0029] During straight-line travel and a small to average spring
compression movement of the piston rod 11 toward the cylinder 33 of
the suspension strut, there is neither a bearing motion nor a
contact of the stop buffer 31 with the cylinder-end surface 35.
[0030] A steering motion, even in association with a
spring-compression motion of a wheel, which is not shown, about the
steering axis 16 leads to a twisting motion within the bearing 15
and, as a consequence, to a wobbling motion of the stop buffer
relative to a hypothetical vertical reference line, for example the
central axis 19. At the same time, however, the suspension strut 3
also moves three-dimensionally about the steering axis 16, so that
the annular space 42 prevents a rubbing contact between the stop
buffer 31 and the piston rod 11 despite the relative motion of the
stop buffer 31 relative to the piston rod 11.
[0031] Thus, while there have shown and described and pointed out
fundamental novel features of the invention as applied to a
preferred embodiment thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
the devices illustrated, and in their operation, may be made by
those skilled in the art without departing from the spirit of the
invention. For example, it is expressly intended that all
combinations of those elements and/or method steps which perform
substantially the same function in substantially the same way to
achieve the same results are within the scope of the invention.
Moreover, it should be recognized that structures and/or elements
and/or method steps shown and/or described in connection with any
disclosed form or embodiment of the invention may be incorporated
in any other disclosed or described or suggested form or embodiment
as a general matter of design choice. It is the intention,
therefore, to be limited only as indicated by the scope of the
claims appended hereto.
* * * * *